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  • Writer's pictureMark L. Johnson

Water Woes XXIV-Equinox Insights

Colorado River Status

Current Conditions

The above normal 2023 Upper Colorado River Basin snowpack has resulted in a 10% improvement in Colorado River reservoir conditions. Reservoir levels as of 9/18/23 are:

Lake Powell-38% full (23% on 2/27/23)

Lake Mead-34% full (29% full on 2/27/23)

Future Conditions (Projected)

The USBR August 24-month Study (see graph-left) projects a Tier 1 Shortage for 2024. We are currently in a Tier 2a Shortage. If the 2024 snowpack is below normal, future shortage conditions could become more serious (see yellow line).

Is Aridification In Play?

The graph to the left shows historical inflow into Lake Powell. Lately, short periods of high inflow are typically followed by periods of very low inflow. Will we see the red, green or black bar in 2024? 2024 will be a good test of the aridification theory.


With one week to go, the 2023 Monsoon Season rainfall is below normal. Total rainfall (6/15-9/19) at Tucson Airport is 4.73 inches versus 5.69 inches (normal). See National Weather Service chart (left).

Assured Water Supply (AWS) Committee

In May, the AWS Committee was formed as a subset of the Governors Water Policy Council in response to groundwater modeling showing dire groundwater conditions in the Phoenix and Pinal Active Management Areas and rural areas. The objective of the AWS is shown in the above slide.

You may recall from previous blogs, that the Designated Assured Water Supply (DAWS) is the official water supply approval for water agencies from the the Arizona Department of Water Resources (ADWR). ADWR issues Designations after receiving and analyzing water demand and supply projections and associated groundwater modeling predicting groundwater conditions 100-years in the future.

The AWS Committee task is to review and make recommendations for updates to Assured Water Supply policies and regulations and to address issues related to groundwater modeling projections. The recommendations must meet certain principles, including:

  • Proposals must protect the strength and integrity of the Assured Water Supply program.

  • Proposals should enable future growth without reliance on mined groundwater.

  • Proposals may not reduce the 100-year requirement or increase the depth to which groundwater may be pumped.

  • Proposals must ensure there is water before growth.

  • Proposals must protect consumers.

TA has been in communication with the Kyle Center for Water Policy regarding the work of the AWS Committee. TA will be issuing comments to the AWS Committee in the coming weeks.

Marana DAWS Modification Update

The Marana DAWS Modification has still not been approved. There have been two more deficiency letters issued for a total of four. It is likely that the Marana DAWS Modification will not be approved until the AWS Committee work is complete.

TA Fundraiser Reminder

If you have not done so already, please donate to the 2023 TA Fundraiser by clicking on the link below:


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